I have a 2018 Edge SEL, new on May 2nd, I am the first owner and took delivery of it with 50 miles on the clock. Absolutely bone stock. Today I had a 300 mile trip and noticed that when I was doing a steady 70 MPH, with cruise on, Waze was telling me I was doing 83 MPH. I did a double take and then stopped, downloaded a GPS information app for my iPhone 8 and 6S and got the same results. Both phones were telling me I was doing 83MPH and the car speedometer was dead on 70 and the cruise said 70MPH. Having worked on GPS at a very intimate level, I am absolutely sure that the GPS derived speed was correct (I had between 7 and 10 satellites in-view so accuracy was pretty high). I am shocked that the speedometer can be this far off on a brand new modern car.... I normally drive 5 over at 70 MPH but 13 over is firmly in ticketing territory!

Any ideas what is going on and how I can get the issue addressed? Has anyone else seen weird issues with their speedometer?

Did you have it plugged into the USB, when performing this test? If so, try it again with the phone unplugged.

I have noticed a discrepancy (phone GPS is always incorrectly HIGHER than speedometer) when CarPlay is active. When I use the phones GPS and compare to speedometer while unplugged, they are both spot on.

When CarPlay is active, your phone will use the Edges GPS for speed determination and it goes a bit screwy.

Did you have it plugged into the USB, when performing this test? If so, try it again with the phone unplugged.

I have noticed a discrepancy (phone GPS is always incorrectly HIGHER than speedometer) when CarPlay is active. When I use the phones GPS and compare to speedometer while unplugged, they are both spot on.

When CarPlay is active, your phone will use the Edges GPS for speed determination and it goes a bit screwy.

I can assure you, your speedometer is the correct reading.

Ding ding ding we have a winner. This was my exact scenario. GPS speed reads normal when not in Carplay mode (i.e.no USB attached). What the heck! As a h/w guy I have no idea how or why this would be the case, but it certainly was the issue. That is bizarre. A big thank you Candurin!